<!!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			var str = "3num";
			console.log(str.valueOf());
			console.log(typeof Number(str));
			
			var arr = [1,2,3];
			console.log(arr.valueOf());
			console.log(arr.toString());
			
			
		</script>
	</body>
</html>